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What causes urinary tract infections?
Last reviewed: 19.10.2021
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Bacteriological studies have shown that the spectrum of microflora depends on many factors:
- the child's age;
- sex;
- the gestational age at the time of the birth of the child;
- period of the disease (debut or relapse);
- conditions of infection (community-based or hospital);
- the presence of anatomical obstruction or functional immaturity;
- resistance of the child's organism;
- state of intestinal microbiocenosis;
- region of residence;
- methods and timing of urine culture.
In various conditions of occurrence of infections of urinary ways Enterobacteriaceae prevail , first of all Escherichia coli (up to 90% of studies). However, in hospital patients, the role of enterococci, Pseudomonas aeruginosa, Klebsiella, Protea increases. According to multicenter studies, the structure of urine microflora in children with community-acquired infection of the urinary tract is the same, although the etiological role of individual species of bacteria may differ significantly from the mean. In most cases, urinary tract infection is caused by one type of microorganism, but with frequent recurrence of the disease and abnormalities in the development of the urinary system, microbial associations can be identified. Among children with recurrent pyelonephritis, about 62% have a mastication infection. There is a hypothesis suggesting a linkage of the urinary tract infection with intrauterine Coxsackie virus infection, as well as with influenza, parainfluenza viruses, RS viruses, adenoviruses, cytomegalovirus, herpes simplex virus type I and type II. Most nephrologists view viruses as a factor contributing to the attachment of a bacterial infection.
Along with bacteria, the development of urinary tract infection can be caused by urogenital chlamydia, ureaplasmosis and mycoplasmosis, especially in children with vulvitis, vulvovaginitis, urethritis and balanoposthitis. Fungal infection of the urinary tract, as a rule, occurs in children with immunodeficiency conditions (prematurity, with hypotrophy, intrauterine infection, malformations, long-term immunosuppressive therapy), which are more characteristic of bacterial associations with fungi.
Predisposing factors to infection of the urinary tract:
- functional disorders of urodynamics associated with hypotension of the urinary system;
- neurogenic dysfunction of the bladder;
- anomalies in the development of the ureters, urinary system;
- vulvitis, balanoposthitis;
- vesicoureteral reflux;
- ureterocele, pyelourethral obstruction;
- decrease in resistance of the organism;
- intestinal infections;
- constipation, impaired intestinal biocenosis;
- catheterization of the bladder, manipulation of the urinary tract;
- hypovitaminosis;
- allergic dermatitis.